Back up profile information in Firefox and Thunderbird

Q I'd like to back up my bookmarks, account settings and address book from Firefox and Thunderbird. I used them for a while in Windows, where I had a dedicated backup program - very useful when Windows threw a wobbly. But in Fedora I can't find either profile. The paths suggested on the Mozilla website don't seem to point at anything resembling either my personal bookmarks (although I did find the Red Hat bookmarks) or my mail files. Searching the filesystem doesn't turn up anything either. Evidently I'm not asking the system the right questions...

A Firefox stores its settings in ~/.mozilla/firefox/default.???, where ??? is an apparently random string. Thunderbird uses ~/.thunderbird/default.???. For example, my bookmarks, settings and address book are stored, respectively, in